A number of devices and fasteners are currently available for blind attachment of objects to structures such as hollow substrates. As used herein, the attachment of an object to a hollow substrate also refers to the attachment of the object to a hollow substrate, plate, body panel, structural framework, wall or any suitable object. However, in many industries, as for example in the automobile industry, difficulty is frequently encountered in fastening a plurality of objects together, such as in securing a body panel to the structural framework or chassis because the inside end of the fastening element extends into a cavity that is inaccessible. As a result, it is difficult or impossible to position a nut in such a manner that a screw can be readily engaged therewith. Additionally, it is often difficult to hold the nut from turning while the screw is being tightened. This difficulty in automobile assembly has been partially solved by permanently affixing a nut such as a weld nut to the inner surface of the innermost of the members to be fastened together in position to receive a bolt or screw after the parts have been assembled. This has often proved disadvantageous because of the impossibility of replacing the nut should it become damaged. Another partial solution was to use rivets. However, this technique also has frequently proved disadvantageous because of the difficulty of removing the fastening device without damage to the members joined by the rivets.
Toggle bolt fasteners are known for providing an attachment device on a blind side of a wall. Toggle bolt fasteners are known and serve for mounting relatively light work pieces and those subject to light external loads on hollow walls. The bolt of these toggle bolt fasteners is screwed into a threaded hole on which the toggle, in the form of a piece of stamped sheet metal, is provided, such that it can be turned or tilted from an insertion position to a locking position at a right angle to the screw. These toggle bolt fasteners often include a pair of legs and a guide member with self-spreading arms, or some complex arrangement to which the anchor member is attached. The toggle bolt fastener is inserted into the mounting hole, and the bolt is rotated into the threaded hole to a length such that it can be inserted into the cavity to the depth necessary to allow the locking element to turn. After insertion into the mounting hole, the toggle bolt fastener is then rotated 90 degrees to the locking position by manipulating the screw. The screw is then driven into the hole until the screw comes in contact with an object that is to be mounted on the hollow wall. The toggle legs are tightened against the inside surface of the hollow wall. Toggle bolt fasteners do not, however, provide the degree of blind control for the attachment device, coupled with restraint requirements, whereby all types of fastening can be achieved. Additionally, these devices often utilize complex arrangements for blind attachment, and such arrangements necessarily compromise the strength of the fastener system.
Some toggle bolt fasteners employ separate spring elements for biasing a toggle element into a toggle locking position once inside a wall cavity after insertion of the element. Other toggle bolt fasteners employ a cam surface engageable with a threaded end of a screw-fastening bolt that is operable to move the toggle into a locking position. In all cases, however, fasteners currently available, including the toggle bolt fasteners, are not removable, since once the toggle element is rotated, the toggle element is not readily rotated for removal without enlarging or otherwise damaging the hole in the wall.